Q From Charlotte Heimann: I found myself urging a dear friend to buck up! in spite of his having been given a distressing medical diagnosis. Why would I say that?
A We use it now to suggest somebody should cheer up, and not be downhearted or oppressed by circumstances. It is a phrase from nineteenth century Britain, derived from those bucks or dandies who were regarded as the acme of snappy dressing in the Regency period. (In its turn, that word came from buck in the sense of the animal, and had a slightly older meaning still that suggested male gaiety or spirit, with unsubtle suggestions of rutting deer.) In its dandyfied sense buck up first meant to dress smartly, for a man to get out of those comfortable old clothes and into something drop-dead gorgeous. Since to do so was often a fillip to the spirit, the phrase shifted sometime around the 1880s to its modern meaning. It seems to have been public school slang to start with, probably from Winchester College, and rather stiff-upper-lip British. It could suggest that the person being addressed should stop acting like a wuss, ninny or coward, as here from Edith Nesbit’s The Wouldbegoods of 1901: “Be a man! Buck up!”, and was something of a cliché at one time in stories of Englishmen abroad bravely facing adversity. From the early years of the twentieth century, it could also be an injunction on somebody to get a move on or hurry up; here’s an example, from D H Lawrence’s Sons and Lovers of 1913: “ ‘Half-past eight!’ he said. ‘We’d better buck up’ ”.